Tracked vehicles conventionally have a drive track that includes an endless belt and a plurality of idler wheels.
A portion of a prior art drive track 128′ is shown in FIG. 1. The drive track 128′ has an endless flexible belt 129′ which has an inner side 129a′ and an outer side 129b′. The endless track 128′ includes a plurality of external lugs (or ribs) 123′ that project from the outer side 129b′ to give the endless track 128′ traction against the snow as the endless track 128′ propels the vehicle, and a plurality of internal lugs 126′ that project from the inner side 129a′. The plurality of internal lugs 126′ defines four longitudinal rows of inner lugs 125′ and two longitudinal rows of outer lugs 127′. The two longitudinal rows of outer lugs 127′ are disposed outwardly of the four longitudinal rows of inner lugs 125′.
A slide frame assembly 44′ primarily includes a pair of spaced apart slide rails 46′ that engage the inner side of the drive track 128′. Two inner idler wheels 50′ and two outer idler wheels 51′ are rotatably connected to an axle 61′ which extends laterally between the slide rails 46′. The outer idler wheels 51′ are disposed outwardly adjacent to the outer rows of lugs 127′. A plurality of longitudinally spaced apertures (or windows) (not shown) are connected to the inner side 129a′ of the endless belt 129′. The slide rails 46′ are covered with slide shoes 41′ and slide over the alignments cleats 130′.
A plurality of lateral rods 200′ (only one being shown) extend laterally through the endless belt 129′ at regular intervals along a length of the belt 129′. The lateral rods 200′ provide reinforcement to the belt 129′. The rods 200′ extend from one lateral side 129c′ of the belt 129′ to the other. The rods 200′ are typically made of metal or fiber filled resin and the belt 129′ is typically made of rubber.
When in operation, as the endless belt 129′ is driven by sprocket wheels (not shown) that engage at least some of the lugs 125′, 127′ and windows and rotates around the idler wheels 50′, 51′. As the belt 129′ rotates, the rods 200′ are successively disposed vertically between the idler wheels 50′, 51′ and the ground. These rods 200′, which are vertically between the idler wheels 50′, 51′ and the ground, support the slide rails 46′ and the idler wheels 50′, 51′.
While the rods 200′ provide reinforcement to the belt 129′, they also increase a weight of the drive track 128′. Furthermore, the rods 200′ limit a motion of the snowmobile when side hilling (i.e. moving at an angle with respect to the slope of the hill). Also, noise is generated when the idler wheels 50′, 51′ run over the rods 200′.
Therefore, there is a need for a drive track having a reduced weight while providing adequate structural resistance. There is also a need for a drive track that reduces noise generation. Finally there is also a need for a drive track that is suited for side hilling.